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parallel to those of another set which are in contact, they are 



said to be conformable. 

 Conglomerate or Puddingstone. Rounded water-worn fragments 



of rock or pebbles, cemented together by another mineral sub- 

 stance, which may be of a silicious, calcareous, or argillaceous 



nature. Etym., con, together, glomero, to heap. 

 Coniferx. An order of plants which, like the fir and pine, bear 



cones or tops in which the seeds are contained. Etym., 



conus, cone, and fero, to bear. 

 Crag. A provincial name in Norfolk and Suffolk for a deposite, 



usually of gravel, belonging to the Older Pliocene period. 

 Cretaceous. Belonging to chalk. Etym., crela, chalk. 

 Crop Out. A miner's or mineral surveyor's term, to express the 



rising up or exposure at the surface of a stratum or series of 



strata. 

 Crustacea. Animals having a shelly coating or crust which they 



cast periodically. Crabs, shrimps, and lobsters are examples. 

 Cryptogamic. A name applied to a class of plants, such as ferns, 



mosses, sea-weeds, and fungi, in which the fructification or 



organs of reproduction arc concealed. Etym., xputfros, kryplos, 



concealed, and yquLos, gamos, marriage. 

 Crystalline. The internal texture which regular crystals exhibit 



when broken, or a confused assemblage of ill-defined crystals. 



Loaf-sugar and statuary-marble have a crystalline texture. 



Sugar-candy and calcareous spar are crystallized. 



Debacle. A great rush of waters, which, breaking down all op- 

 posing barriers, carries forward the broken fragments of rocks, 

 and spreads them in its course. Etym., debacler, French, to 

 unbar, to break up as a river docs at the cessation of a long 

 continued frost. 



Delta. When a great river, before it enters the sea, divides into 

 separate streams, they often diverge and form two sides of a 

 triangle, the sea being the base. The land included by the 

 three lines, and which is invariably alluvial, was first called, in 

 the case of the Nile, a delta from its resemblance to the letter of 

 the Greek alphabet which goes by that name, A. Geologists 

 apply the term to alluvial land formed by a river at its mouth, 

 without reference to its precise shape. 



